1. Field of the Invention
The present invention relates to steam cleaning compositions. More particularly, the present invention relates to stable, low-foaming steam cleaning compositions for use in cleaning carpets, fabrics and other inanimate surfaces.
2. Description of the Related Art
Fabric and carpet fibers may become soiled or stained upon contact with water and proteinaceous materials, particulate matter, oily/greasy type soils, oxidizable materials, and various other materials. Cleaning compositions are formulated for use on fabrics and carpets.
An important property of cleaning compositions is their propensity to foam. In some situations, a high level of foam is desirable as an indicator to consumers that the product is still working as a cleaner. An example of this would be in hand dishwashing. A lack of foam might be a signal to the consumer to add more products to provide additional cleaning.
However, in other areas of product use, low to negligible levels of foam generation is required. In areas of use where the cleaning product is subjected to high levels of mechanical agitation such as in steam machine carpet cleaning, heavy foam generation results in foam filling the machine and possibly flowing out of its containment. There is also the potential for the foam to seep into machine parts and damage the machine or, at the very least, cause a great deal of inconvenience for the consumer. Furthermore, compositions that are low foaming under other conditions may produce greater, unacceptable levels of foam under the conditions of typical steam cleaning machines.
Today's steam machine cleaning formulations typically are formulated as concentrates, which are then diluted for use. Certain popular machines actually take the detergent concentrate and make the dilution according to preset conditions programmed by the manufacturer. In such cases, it is especially important to have a low foaming product since high settings on the machine will typically be above the recommended product dosage level. Low foaming products help aid in machine safety as well as consumer satisfaction.
Formulating low foaming compositions that are effective in cleaning poses difficulties for the formulator. For example, many commonly used surfactants, particularly certain anionic and amphoteric surfactants, typically are high foam generating surfactants. One method of reducing foam in cleaning compositions is the inclusion of silicone compounds as defoaming agents. However, typical silicone compounds used as defoaming agents could potentially promote resoiling of the carpet or fabric. Further, under typical steam cleaning conditions, the silicone in the cleaning composition may destabilize and separate out of solution leading to the potential coating of machine components with silicone material.
The development of a quick, reliable and easy-to-use predictor test method for foam generation is essential to the development of suitable formulations for today's steam machines, both in terms of machine safety and consumer convenience. Additionally, a good predictor test method will save detergent formulators valuable time and cost in the testing. While outside laboratory tests that use the steam machines of choice can be used as a final method of product acceptability, the service can prove costly and time consuming if used as a screening method for all prototypes.
Of the various dynamic and static test methodologies currently available, the Ross-Miles Method is the most widely used, ASTM D 1173-53 and B. M. Milwidsky and D. M. Gabriel “Detergent Analysis, A Handbook For Cost-Effective Quality Control”, 1994 (Micelle Press), pp. 42-43, 175-176. Unfortunately, at the dilution levels typically employed by this method (1% or 0.1%) it was found that false positive results could be obtained. For example, the foam profile of a prototype formulation could be judged low and acceptable in the lab using the Ross-Miles Method. However, when the same prototype formulation is sent for outside lab testing using actual steam machines, the agitation and product concentration employed resulted in unacceptable results. Based on these types of misleading results, a more reliable lab test method to predict foaming profiles in steam cleaning machines is required.
In addition to providing acceptable cleaning performance with no consumer downsides such as too high a foam level or a propensity for resoiling, cleaning compositions must be stable in storage. Furthermore, there is great consumer demand for the inclusion of peroxygen compounds in cleaning compositions, particularly in steam machine cleaning compositions. Peroxygen compounds increase the cleaning range of typical cleaning compositions. However, peroxygen compound containing compositions pose a great challenge for composition formulators, especially in the realm of stability.
A typical consumer may store a cleaning product for many months before use under less than ideal conditions. During storage, the components of the composition ideally should not separate from each other or, if they do, simple shaking the container should result in a completely homogeneous solution. A homogeneous solution during use is necessary for a composition to remain fully effective. The problem of compositional instability is further exacerbated when a peroxygen compound is incorporated into the formulation. Peroxygen compounds easily degrade and their effectiveness as decolorizing and cleaning agents is quickly reduced upon degradation. Furthermore, degradation of a peroxygen compound generates gases that can cause swelling and potential bursting, of the package in which the cleaning composition is provided.
Another concern that is often forgotten is the potential aggressiveness of a peroxygen compound containing composition and its effects (both long term and short term) on the various machine components that are exposed to the cleaning solution under the typical use conditions. Thus, compositions containing these types of materials must not only be stable, but also safe to use by consumers on their carpets and safe to use in various steam machines.
Thus, a low-foaming, stable steam cleaning composition that has a peroxygen compound that is effective for cleaning carpets and fabrics, and that is safe for use on fabrics and carpets, and safe for use in steam cleaning machines, is required. However, no current steam cleaning composition having a peroxygen compound, let alone one that is low-foaming, stable, effective, and safe for use is known. Accordingly, a low-foaming, stable, peroxygen compound containing steam cleaning composition that is effective and safe for cleaning carpets and use in steam cleaning machines is provided. Further, an inexpensive lab test for predicting and more closely simulating the foam profile of a steam cleaning composition in actual steam machines is also provided.